TH67320B - Recovery of non-ferrous metals from a by-product of the zinc industry. And lead by using a submerged plasma (submerged plasma). - Google Patents

Abstract

------04/01/2018------(OCR) Page 1 of 1. Abstract of Invention. This invention describes a single-step thermal separation process for the recovery of non-ferrous metals from zinc slag, particularly from zinc and lead industrial by-products such as goetite and jarosite. A process for recovering metals from industrial Zn slag containing Zn, Fe, and S is defined, where Zn is smoked, Fe is molten slag, and S is oxidized to SO2. The characteristic feature is that the smoke of Zn, the molten slag of Fe, and the oxidation of S are performed in a single-step process by melting the slag in a furnace incorporating at least one submerged plasma burner, which generates an oxidizing gas mixture, and by feeding a solid reducing agent into the molten material. This process results in the oxidation of S and the formation of molten Fe slag while simultaneously causing reduction and the production of metallic fumes such as Zn. ------------ Revised Invention Summary 23/03/2016 This invention relates to a single-step thermal separation process for the recovery of non-ferrous metals from zinc slag, particularly from zinc and lead industrial by-products such as goetite and jarosite. A process for the recovery of metals from industrial Zn slag containing Zn, Fe, and S is defined, where Zn is fumed, Fe is formed into molten slag, and S is oxidized to SO2. It is characterized by the fuming of Zn, the formation of molten Fe slag, and the oxidation of S being performed in a single-step process by melting the slag in a furnace incorporating at least one submerged plasma burner, which generates an oxidizing gas mixture, and by feeding a solid reducing agent into the molten material. This process results in the oxidation of S and the formation of molten Fe slag, while simultaneously causing reduction and the production of metallic fumes such as Zn. ----------------------------------------------------------------- This invention relates to a single-step heat treatment process for the recovery of non-ferrous metals from zinc-containing slag, particularly from zinc and lead industrial by-products such as goetite and jarosite. The method for industrial Zn slag recovery involving Zn, Fe, and S is defined, where Zn is fumed, Fe is formed into molten slag, and S is oxidized to SO2. Specifically, the Zn metallic fume, molten Fe slag, and the oxidation of S are performed in a single step by melting the slag in a furnace incorporating at least one subflux plasma burner, which generates an oxidizing gas mixture, and by feeding a solid reducing agent into the molten mass. This process involves the oxidation of S and the formation of molten Fe slag, while simultaneously causing reduction and smoke from substances like Zn.

Claims (8)

------04/01/2018------(OCR) Page 1 of 1 page. Claims 1. A process for the recovery of metals from industrial Zn slag containing Zn, Fe, and S where Zn is smoked, Fe is melted into slag, and S is oxidized to SO2 in a single-step process involving the smelting of the slag in a furnace incorporating at least one submerged plasma burner, which generates an oxidizing gas mixture, and the feeding of a solid reducing agent into the top of the slag. 2. The process as described in Claims 1 where at least one submerged plasma burner is of the non-transferable type, and where the oxidizing gas mixture is injected into the slag phase. 3. The process as described in Claims 1 where the amount of free oxygen in the oxidizing gas mixture is optimized as stoichiometrically required. (Stoichiometric) for at least the major oxidation of S and Fe, and the amount of solid reducing agent is optimized as stoichiometrically necessary for at least the major reduction of Zn. 4. The process according to Patent 1 in which an oxidizing gas mixture is generated by feeding a mixture of air and gaseous hydrocarbons into at least one submerged plasma burner. 5. The process according to Patent 1 in which industrial Zn slag contains In and/or Ge, leading to vaporization. 6. The process under claim 1 where industrial Zn slag is groatite. 7. The process under claim 1 where industrial Zn slag or a solid reducing agent contains Cu, leading to the formation of a Cu matte phase. 8. The process under claim 7 where an oxidizing gas mixture is optimized to obtain a Cu matte with more than 40% Cu by weight. ------------ Revised 23/03/2016 1. A process for recovering metal from industrial Zn slag containing Zn, Fe, and S where Zn is smoked, Fe is molten slag, and S is oxidized to SO2 in a single-step process involving the smelting of the slag in a furnace containing at least one submerged plasma burner, resulting in the formation of an oxidizing gas mixture. 1. By feeding a solid reducing agent into the top of the molten slag. 2. The process according to Patent 1 where at least one submerged plasma burner is of the non-transferable type and where an oxidizing gas mixture is injected into the molten slag phase. 3. The process according to Patent 1 where the amount of free oxygen in the oxidizing gas mixture is optimized as required stoichiometrically for at least the major oxidation of S and Fe, and the amount of solid reducing agent is optimized as required stoichiometrically for at least the major reduction of Zn. 4. The process according to Patent 1 where the oxidizing gas mixture is generated by feeding a mixture of gaseous air and hydrocarbons into at least one submerged plasma burner. 5. The process according to Patent 1 where the industrial Zn slag contains In and/or Ge, leading to vaporization. The following are examples of processes involving the formation of metal fumes: 6. The process under Patent 1 where industrial Zn metal slag is goethite. 7. The process under Patent 1 where industrial Zn metal slag or a solid reducing agent contains Cu, leading to the formation of a Cu mat phase. 8. The process under Patent 7 where an oxidizing gas mixture is optimized to obtain a Cu mat with more than 40% Cu by weight. 9. The process under Patent 1 where the oxidizing gas phase is optimized to obtain a mat with less than 5% Fe by weight. 1. Process for recovering metals from industrial Zn slag containing Zn, Fe, and S, where Zn is fumed, Fe is molten slag, and S is oxidized to SO2. A characteristic feature is that the Zn metal fume, molten Fe slag, and oxidation of S are performed in a single step by melting the slag in a furnace equipped with at least one subflux plasma burner, creating an oxidizing gas mixture, and by feeding a solid reducing agent into the molten mixture. 2. The process described in Patent 1, characterized by at least one non-transferable subflux plasma burner, where an oxidizing gas mixture is injected into the molten metal residue phase. 3. A procedure under claim 1 or 2 whereby the amount of free oxygen in the oxidizing gas mixture is optimized to meet at least the stoichiometric requirements for the major oxidation of S and Fe, and the amount of solid reducing agent is optimized to meet at least the stoichiometric requirements for the major reduction of Zn. 4. Any of the processes under claims 1 through 3, where an oxidizing gas mixture is generated by feeding a mixture of air and hydrocarbon gas into a plasma burner. 5. Any of the processes under claims 1 through 4 where industrial Zn slag contains In and/or Ge, leading to vaporization and the generation of metal fumes. 6. Any one of the processes under claims 1 through 5, where the industrial Zn slag is goetite. 7. Any of the processes under claims 1 through 6 where industrial Zn metal slag or solid reducing agents contain Cu, leading to the formation of a Cu phase mat. 8. A process pursuant to claim 7 whereby the oxidizing gas mixture is optimized to obtain a Cu mat containing more than 40% Cu by weight, or ideally more than 50% by weight.